Shocking customer service

I loged a call with telcom disputing my billing for the month of Jan 2019, in terms of data used, this was on the 11 Jan 2019, the call centre representor at the told me that I couldn't log the dispute then, I that I had to wait until the end of the month to log the quiry. I disputed this and was told this is not how telcom works. I called back on the 3 rd April 2019, to check up on the dispute and was told that no case was loged. The call centre represents on the 3rd told me that I had to log the dispute on the 11 of Jan 2019. 2 Representors of telcom, different stories told. I was for more than 3 hours on the line, at my exspence trying to resolve this, and this month my April 2019 invoice is more than usual. Shocking customer service from telcom. I rate telcom a -1 on their overall customer service and won't recommend to anyone.