Not happy with Cancellation process or service

I joined VOX Telecom in April for the amount for R 554 within the first 6 months my monthly instalment was increased by VOX and the amount went R 554 to R 634 I requested to cancel my FIBRE line as I am moving , I was told that I need to pay an cancellation fee of R 1500 excl. VAT - With VAT it is R 1725 They also want the router back that was installed in APRIL

I understand that the router needs to go back , But do not agree with the R 1725 penalty fee/ Cancellation fee, as no installation was done , a cable was just pulled through an existing infrastructure. and the fact that my instalment was increased within 6 months .

I do not agree with with this type of service , and not very happy with this, I will not make use of the service of VOX ever again.