I do not owe Blue Lable Connet

I app**** for a contract from Blue Label and the phone was delivered 2021 December 11th on the same day I realized the phone that was delivered was not the one I was expecting. I called Blue label the next day and to cancel my contract and for them to fe5ch their phone.. they took 3 month to collect the phone while I kept on calling them. Last year March the phone was collected but I am now getting calls from DMC telling me I am being with my payments. Called Blue label customer care and I was told they will call me back. Now I received this message below Can someone sort this out. This is really messing up woth my credit record.. I do not owe BKUE LABEL CONNECT A SINGKE CENT.

Michelle, 50% discount off your Blue Label Connect account is still valid. Visit http://d.dmc.co.za/VKKHdF or WhatsApp http://d.dmc.co.za/vxoUNR today. *** DMC: Resolving Debt Fairly