It’s difficult when you’re so close to the end of your course. You’d need to find a course that matches what you’ve done so to date so that you get the full teaching to meet the requirements of the degree, due to the modular system that most universities work with. My advice is probably going to be to stick with the university and course you’re currently undertaking. Reasons for this are : entering in year 3 for the final year is difficult to arrange, get accommodation, settle and understand the organisation/ structure of a new course and new university. It’s why most universities discount the first year results in overall degree classification. Perhaps to cover all grounds so you feel like your knowledge is where it should be, you could do a full time masters after your degree at a university where the teaching is recognised as being undertaken by properly qualified lecturers.
On another note, I’m finding it hard to understand why your current university is allowing other students to teach you and that you don’t have proper lecturers. It sounds like you need to contact someone high up in the university about this, perhaps the Dean of the School to get answers as to why you are not getting properly taught. I’d normally suggest your Course Director in the first instance but as they would know all the lecturers and are responsible for their deployment, it sounds like you need to go higher. I’m quite horrified that you are paying this money and not getting taught by professionals.