Unfairly treated and under paid.

Good evening. I started working at Ophifield t/a Toy wholesalers on the 15 of March 2021 i was promised comission and over time, i was supposed to sign a contract the first week of being there, i am still waiting for a contract till today. I only received my pay on the 1st of April 2021 without over time and commission. I received a full months pay and when i went to the owner (Tyrone Armist) to find out why he is paying me a full salary his word were its for over time and commission. So it was left at that! this month April 2021 i worked the full month and i worked over time and now i got paid today but only half of my salary. I went to the owner (Tyrone Armist) and asked him about it, his words were he would draft a email and send it to me. I cannot work in this way.