Don't take a wifi package with Supersonic

I took a LTE package through Best Internet with supersonic. First of all they did not tell me that the router is lock to a specific location so I called to cancel my wifi package because I moved from the place where I was staying. A lady from Supersonic then phoned and asked why do I want to cancel, so I explained the above mentioned. She then said no I don't need to cancel and they can unlock it. Today I found that they debited me for R1566,33 where as my wifi package is R399.00. I phoned in and another lady told me that there is a cancellation fee to pay for all the equipment that has to go back. This was never mentioned to me. They are so quick to sell you something but then don't tell you everything that they charge. On the invoice that they send me, it says R399.00 and not R1566.33.