Customer 6 (bad)

Customer came in to transfer his now ex-wife’s phone off of his account. I have dealt with this guy before and he is a big jerk I’m more surprised she married him then divorced him. The first time i encountered this couple it was only the wife, i provided her with an offer on their account. Save around $30/month or throw in a tablet for her and one for her husband, i had went over everything in detail and even provided a hand written quote sheet with all the charges itemized and even took a rough estimate at those darn surcharges that very month to month. I ended up quoting them about $1 more than they were paying before. The next month the couple comes in and argues with me for over an hour, they bring in the quote sheet and bring in the bill claiming it’s not what I quoted them. So I take a look at the quote sheet and the bill because I don't remember the couple considering I see a lot of people on a daily basis. Well they were right my quote was off, they didn't pay $1 more they paid 50 cents less so the bill was $1.50 less then I quoted them. Over this hour I’m getting pissed because who really spends the time and money to go to a store to argue with someone about your bill being wrong when you are benefiting from it. The husband kept saying “I understand what you are saying, we are saving money each month but that is not what you quoted my wife”. Some people you just cannot please, so I finally get them to leave. They come back the next month again, we talk with them for over an hour, this time instead of the bill being off they want to return everything they bought 2 months ago and take the $30 savings instead, the reason they gave behind this was he would rather not have the tablets as long as that meant I didn’t get commission off of their sale and that they might go to the next closes store to rebuy them. I tell them if you change your mind it has to be done within the return policy which is 2 weeks not 2 months. He flips out claiming we never gave him the offer to save the money and that we forced him into the tablets. Meanwhile I’m confused because I still have both quote sheets on file showing that when his wife came in she was offered both options and chose the extra devices over the monthly savings. Finally, I give up on this guy and pass him off to someone above me because they don’t pay me enough to deal with idiots like him. The most recent time he came in was with his ex-wife as I mentioned above to move her off of his account. My manager explains everything to him that if we do that in the store it does not transfer the 2-year agreement for her phone and will charge the remainder of her payments on his next bill which is somewhere around $400. But if he does it online it will transfer the agreement which is true. She followed that up with offering to assist them by letting them use her computer to fill it out. The ex-husband is getting pissed and refers to my manager as a “bandanna wearing bitch” right in front of her and his ex-wife. Well she kicked him out of the store and tells his ex-wife that she already got the confirmation from him to do the transfer so she will assist her after he leaves. The ex-wife said its ok she can do it at home she just wants to make sure she has what she needs to do it. I am not sure why we have people who act like this in this world but I have a feeling the ex-wife was only following in his footsteps when she came in with him arguing on their 2^nd visit. Let me know what you think, if you saved $1.50 over what you were quoted on a bill around $250 would you complain? Would you even notice? I know a lot of people who don’t even read their bills, do you? Should I have taken blame for the billing issue? At what point should we be able to ban a customer for stupidity? Comment below.