Poor Service - Increase prices for no reason.

I have had a interne/LTE service with Cell C for about 3-4 years now. Reached out for a call back to no avail - however when it’s something that will benefit the company they quick to try and sign you up for stuff that’s not needed. My bill has always been R129 - for some reason last month it was R259 with no explanation, this month I see a invoice for R320, again now explanation. I would like a call back.