Poor Customer Service & Communication

I've always had good experiences with Superbalist, but I'm extremely disappointed in their lack of communication and customer service.

I won a competition this year and was given a voucher. When I tried using it, it says the voucher has been used. I sat on the phone the entire day, calling for over 30 minutes for someone to pick up and assist me. After 6 calls, someone assisted and told me my voucher was used in 2018. I used all my airtime because no one was picking up to assist me. She told me I'd get a new voucher within an hour, the entire day passed and I received nothing. I'm so disappointed in the lack of professionalism and customer service.