Modem Software Incompatible

I bought a D-Link modem on the 30 April 2015. This worked fine until the 4 October 2015, when I suddenly got an error message about the administrator had block the software, because it was not trusted. I had not changed any of my PC settings. I uninstalled the software but the problem persisted. I called the Customer Support Line, and was told it was a network problem and should be resolved within 24 hrs. I called again the following day and was told it was a problem with the modem software. I was told the nearest technician to Kempton Park was at Eastgate and I was to take the modem there, I took the modem in on the 12 October and was told the modem was fine, I had to bring in the PC on Thursday the 15 October because the technician would be available then. I took the PC in on the 15th and was told the problem was all because I had installed Windows 10. I installed Windows 10 in the middle of August 2015. At no time prior or since I installed Windows 10, have I seen any communication from Telkom warning customers that the D-Link modem does not work with Windows 10 and they have no idea how to fix the problem. I spent R399.00 on a modem which now doesn't work.