Many thanks for your patience, I am pleased to be able to continue assisting with your query now. First of all, I am sorry to hear about the issues you have experienced in your situation.
This can indeed be considered a breach of trust and confidence, especially if there was no clear indication that you were willing to give up the class after the changes were introduced. Your original intention may have indeed been to give it up but that was before they introduced the pay rise and before you started teaching it. Once these happened, it could have easily changed your approach to this and you may no longer have wanted to leave. Therefore, the employer should not have assumed that this was still the case, based on an outdated opinion. They should have checked with you beforehand and determined what your intentions are before coming to a decision.
At this stage, this is best dealt with through a formal grievance. You can get a detailed explanation of the grievance process here:
In summary, an employee is expected to submit their concerns in writing and send them to their line manager, or whoever is nominated as the person to send grievances to under an official workplace grievance policy.
The complaint should include details of what the grievance is about, any evidence that may exist which is relevant and also what the employee wants their employer to do about this issue.
Once the grievance has been submitted, the employer is expected to arrange a formal grievance hearing, inviting the employee to attend and discuss the nature of their complaint. The meeting is also as an opportunity to ask for further clarification or information, as required.
Following the meeting, the employer will take time to consider all the issues and evidence and then make a decision, communicating it to the employee. If the outcome is not to the complainant’s satisfaction, they can appeal and get a second opinion from a different person assigned by the employer to consider the appeal. Once the appeal is also completed, that brings to an end the formal grievance process and there is no option to escalate it further internally.