I expect that someone with specialist knowledge will arrive to give you some good advice soonish. In the meantime, do you realise that after two years employment you then have a certain security. You say that you have been working for over a year. This means that if you rock the boat too much you could be vulnerable to some kind of retaliation.
I work for an estate in North Yorkshire. I have been here over a year. I still do not have a contract, every time I ask they say ow it's still been worked on. My concern is when I leave next year, will they pay my overtime. I heard they won't because it's in the contract. Obviously I don't have one yet.
Don't touch them owe me £500 since January 2019 make excuse after excuse. Seem they always have software problems sending money out. Keep saying they will call back or email nothing been chasing it now for 6 mths the phone staff always have the same banter we will chase it up and get back to you then nothing!