2nd time getting bad service at Tekkie Town RCS

In 2014, I paid my Tekkie town account at the stoneridge store on time and my payment was not allocated therefore I kept on getting sms'es about not paying my account only to find they have not allocated my payment. Now again last month, they repeated the same thing but only now they charged the collection fees and indicated on my transunion credit profile that I did not pay my account. Even though, it was their fault. I am not disappointed but I am so angry cause my credit rating is going to be affected for something I did do - pay the account on time. Now they are not getting back to my emails or calling me to tell me who is going to sort this out but if they want to offer credit and sell you stuff they call you 10 times a day. I am beyond what words could explain with the kind of service I am getting from them and right now I just want to close the account and throw the card where the sun doesn't shine!