Called about my internet being out after only havi...

Called about my internet being out after only having it for 50 days. I paid for my own modem, therefore they said it will be $100 to have a technician to come out and figure it out. I told them many times it is not hardware based. I know for a fact because I went out and bought a brand new modem/router. Called their technical support and gave them my new MAC Address. Still no internet. Funny thing is I went earlier to the apartment leasing office and was told their internet was out and ironically theirs now works and mine is out shortly after. I told them I should bill them $100 for troubleshooting them for being the issue and not me.