Terrible service from Cell C

I have been trying since December 2019 to get the credit amount due to me paid back. I did not renew my data contract with them when it expired after 24 months. I gave sufficient notice of my intention to not renew, Although not a big amount, the money belongs to me and there is no reason why the credit amount should stay in my a/c as I am no longer a customer of Cell C. Several e-mail requests have been ignored. They are quick to make deductions from a persons bank account, but conveniently forget and ignore to pay back money belonging to a customer. I will never be a Cell C customer again.