Faulty Devices

I recently cancelled my Telus home security contract about 2 years short of the 5 yr term. I was first having multiple issues with the garage door opener which kept causing the door to get stuck while closing. I contacted Telus and was told that they reset it and should be good from now on, well it wasn’t fixed so I put up with it while I waited for my contract to end. 
More recently my basement flooded and I found my water sensor floating on the water without alarming. This was the last straw so I cancelled my contract but instead of Telus offering a refund for the 3 years they had me pay for faulty goods,they billed me for the remainder of my contract .

I will not pay anymore for those devices. I have returned them to Telus so please retract that final bill.