Struggling to get my paid up letter

Had done an early cancelation with Vodacom in the first week of May. Till to date I have not received my paid up letter. When I do a follow up it's either my emails are being Ignored or they inform me via social media platforms that they will revert back to me with feedback. It's been 3 weeks now and I am also waiting on them to update on the Bureau. Vodacom doesn't care about customer service at all! I really do not know what to do in order to get my letter.