Nonsense service and poor administration

The frustration of being a customer at this company is being the level at which I can explain how ****ed I am, the embarrassment I face every time I have to do a purchase, second time my account is blocked for no reason, no communication, just a **** up, I’m told I can buy because I have errors of 500 and the penalty is coming from paying online that’s how interest are inccured, why give an online option for to pay if I now being penalised for it, I wanted to pay that 500 immediately I was told I can only buy tomorrow what nonsense is this, I pay more than what my monthly instalment requires can someone unblock my account and have the decency to call and tell me what the **** is happening