Bad service and return

I ordered Christmas clothes from them and found 5 items were way too big sizes and i repacked them and ordered a return collection same day 11 of December . The package was supposed to be collected on the 13 of December but it was not collected their driver **** that the package was not ready so he didn’t collect it so it was rescheduled for the following day.. The following day same thing happened again and the package was not collected. I called them them on the 14 after seeing the sms that the package is rescheduled for another day and they promised me that they will sure the package is collected not later than the day but it was not. Got another sms to say parcel could not be collected due to admin errors. Now i feel so helpless because they say they dont have an alternative way of collecting the parcel except for their corrier yet its been 9 days waiting for them to collect and seems like its never gonna happen because I called them they told me that i never booked it. How because they are one rescheduling everyday and now it is my fault to that they did not book me..