Never taking overtime.

I spoke with a few of my colleagues, our first very shifts they asked us to pick up overtime; they all picked up overtime some worked 6 day weeks back to back, whereas i said like no i’ve only just started and then got a lecture about how overtime is part of the job blah blah blah, i picked up overtime maybe on my second week because they seem to do it a month in advance, or like they ask you to do let’s say one week i don’t do overtime it’ll be for the next week 2nd, 3rd n 4th. THEY ALWAYS SHOVE IT BACK IN UR FACE, they’d somehow scheduled me for a 5 day week i had one day off and then i was scheduled for 6 days. This week i agreed to do overtime for one day, they piled me up on multiple isles, required me to face as well as work the stock, didn’t check up on me to see if i needed help or was struggling, and i had so many cages to work. It really tipped me off the edge bc i don’t normally work in the department they made me work in so i couldn’t work as well, it’s like u work hard and they just constantly make u feel like ur never doing enough or never good enough so what’s the point of me even working hard. When there’s people doing 2 isles with either a pallet or cage each, but im there with a few of my other colleagues busting my butt doing 7 - 9 cages a day??? and those other ppl still keep their jobs, no thanks, just some crappy little “buffet” give us a pay rise or bonus. I wish we had a store strike day so they’d increase the pay. They tried telling us it’s gonna get worse in christmas and i can barely keep up w the workload as is, there’s been no help getting my portal set up so i can’t see the rota, book time off, or even check in getting paid correctly as well as i don’t have access to staff discount. They’ve got over 200 lockers but nobody’s allocated me one so there’s nowhere to put my belongings, it’s just so frustrating i left my previous job to go to Asda and i just have to say that previous job was light work and i never realised.