Vodafone Missing Line Not Cancelled

I am experiencing a serious grievance regarding the Vodafone line with the number 0539 9** 41 11, which I am not actively using at the moment. I was informed that a refund of ₺3,500 would be made and that this amount would be reflected on my March invoice, but no such refund has taken place. When the commitment period of my invoice ended, I was called by Vodafone customer service and asked whether I wanted to renew my tariff. During this call, I clearly stated that I did not want to renew my invoice and explicitly requested the cancellation of both my line and my invoicing. Despite this, my line was not cancelled, the invoicing continued, and in addition to the ₺3,500 refund that was not made, a new invoice amount of approximately ₺600 was added. In total, an unjust charge of around ₺4,100–4,200 has been created against me. During this process, I have contacted Vodafone customer service more than five times. In these calls, I was usually told that the refund would be made, and a refund link was sent; however, when I accessed the link, no refund appeared and I could not obtain any concrete result. I live in Malatya, and when I visited a Vodafone dealer, I was directed back to customer service, and the problem still has not been resolved. I request that the unjust total amount of approximately ₺4,100 reflected on the line 0539 9** 41 11 be cancelled or refunded to me and that this line be completely terminated. I also request that I be contacted as soon as possible via my currently active number 0539 8** 82 44 so that my grievance can be resolved urgently. Additionally, I kindly request that the complaint I submitted via Xolvie not be deleted.