Telkom is ripping me off

My name is Louise Moeketsi residing in Mafikeng I have a Telkom home WiFi with (Open Server)which the contract started on December 2024. And our initial agreement was am going to pay R315. Everything was fine until last week Friday on the 3rd of October 2025 when I was billed twice. I called your office to rectify this error but it's pretty clear that my words fell on a dead ground. On this month i was charged R5710.06, I went to Telkom shop at the crossing mall here in Mafikeng but I was told they can't help unless I pay R5710.06...i mean how on earth can you charge me this amount please help my account ***