Thank you for your previous advice. I am now facing a new…

Thank you for your previous advice. I am now facing a new situation, and I need your advice once more.I received a letter from a debt collection agency, on a total sum of £8146.13, which seems to comply with the pre-action protocol for debt claims of October 2017, it mention a contract date which matches the date I paid a deposit (£2750) on the 24/5/16. The deposit was not mentioned in the debt claim. This date does not match the date when I signed the registration form, which was the 9/5/16. There was also registration fee to the school, which was paid separately.I plan to dispute the letter, and claim my deposit back.I plan to substantiate my defence on the following:1) At the point of registration, the school only had year 7 and year 9, and it was mention on their website that they provide up to 16. When I signed the agreement, there was an OFSTED report (dated 22nd April 2016) stating: “Wetherby Senior School is a secondary independent day school for boys aged 11 to 16 years which opened on 7 September 2015 in newly refurbished premises.”
2) During autumn 2017, the school announced that they will open, starting September 2018, study program targeting a-levels. The school headmaster even stated that he hope that my son will do his A-level with them. I never provided any positive acknowledgment to that.
3) On March 1st 2018 the school sent an email stating that the 2nd of March is the deadline of submitting A-Level options. The email included an attachment which stated that “all boys needs to have the form signed by a parent/guardian and their tutor”. I have not signed this form, and the school didn’t follow up on this.
4) I never shown an intention to move my son from their GCSE program into their A-levels program, mainly because the school failed to nourish my son’s educational success in science, which he experienced in his previous school.
5) I have evidence in emails that my son was being considered by his teachers to bad in biology, which is the main field my son is interested in. In his GCSE exams my son excelled in this fields, only after deep intervention by me that included psychological counselling and private education program outside the school.Regarding disclosure, I plan to ask the school to disclose the following:1) Copies of signed contractual agreements between myself and the school, in particular anything that mentioned a-levels.
2) Evidence that A-Levels were being offered as part of the senior school educational schedule at the date of registration (which didn’t exist).
3) All communication from the school to me regarding my son performance, as well as all other administrative communications to me in 2016,2017,2018.
4) All internal communication relating to my son, in particular my son’s performance in 2016, 2017 and 2018. Also, all A-levelI would need your advice on the following1) What is your opinion on our disclosure request? Is there anything else you recommend me to ask from the school as part of the pre-action protocol?
2) If this dispute will go to court, will it be discussed in small claim court? Can we make sure it will not go to “normal” court which will cost me a fortune?
3) Is there anything else you would recommend me to ask/do/send as part of this pre-action activities that will strengthen my case? Examples will be – do I need to send copies of email that the school sent to me? Evidence for the extra education my son had to take?