Glasgow City Council are responsible for emptying the bins not WSHA.
If your bin is not emptied/missed bin collection or overflowing, you need to contact Glasgow City Council.
You can contact them via the My Glasgow app: https://www.glasgow.gov.uk/article/1853/Save-Time-Go-Online
By clicking on this link: https://www.glasgow.gov.uk/article/1601/Report-a-Missed-Bin
Or by calling Glasgow City Council Environmental Services on 0141 287 1058.