Pathetic service and now follow ups

Good day

i was on contract with Vodacom till December 2016. Upon expiry of my contract I moved to another service provider but I am still receiving sms'es stating that there is money outstanding. I have received calls and have requested clarity of how it would be possible that I have an oustanding amount when I paid via debit order and there was no problems experienced. I have the last invoice for December 2016 and proof of the debit order being processed. I am concerned that this will negatively impact on my credit record although I am in no fault.

All attempts to contact vodacom have yielded no results.

Regards

Sunjith