account cancelled but keep getting billed

Hi,

I cancelled my Telus home services account via phone for March 8th (it showed up as "cancelled" in the online portal)
I returned my hardware on February 17th.

After March 8th I received another bill for the billing cycle starting March 9th.
I called Telus again and explained. The person who helped me removed my autopay from the account and corrected the incorrect bill (or so I assumed)

Now I'm getting another email, demanding a late fee of $4.54 for the billing cycle of March 9th to April 8th.
This is getting very tedious. 

Can someone from Telus please fix this once and for all? 
Thank you,
Tilman Paulin