No help

I have been trying for 3 months to get the payment I made reflected on my account. No success. Every time i phone the answer is we will escalate it and send proof of payment, which was done numerous times. I am so frustrated as the account went up and still no joy. I cannot get through to customer care and nobody can help me sort out this problem. I would like to settle my account but I am not going to pay double for people who isn't willing to help or do their work. Who can I contact to get this sorted out as this is ridiculous.