Company Breach of Data/Contract. Need Urgent advice

[tpsure]

I recently worked for a company which advised for a particular role which i had years of experienced in. They asked what salary i was looking for as they appeared to be open to any salary that i requested ( or so they said) . I gave them a figure and with that i was told they will get back to me at the end of the week. Later that day, they called and offered me the job but on the condition that i take a £1000 pay cut. I was not happy with this but needed a job, so accepted it. Within a few days i was isolated and bullied by my colleagues and was not sure why It was so intense, until one day the bullying got back that one of the bulllies confessed the reason i was bullied is because they found out what my salary was from the management. I also found out the company told them that i was a manager. I confronted the management about it and was basically lied too. The man who interviewed me said i was given the salary for a managerial role. I advised him that this was not discussed at the interview and i did not agree to it and my contract also did not reflect it. I also asked about the breach of data in relation to my salary. They seem to shrug it off . I was not given an explanation or an apology. Time went on and the bullying increased , my colleagues would leave me with piles of work while they took long lunch breaks . When questioned i was told they company again stated i was a manager, so i should do the work. I was lied to constantly by the management at the company. So decided to ask for a meeting , to which i basically told them what i thought about the poor practises . I was fired and told i was i would only recieve 1 week in Lieu. Would like advice as i would like to pursue this in court