Advice on a dismissal accused of theft less than 2 years service

[Twentyman71]

Can anyone please give me some advice. My son was accused last July of the theft of 2 items from the workplace. 2 days previously to the items going missing he was not on shift. The day after the items where discovered missing he returned to work and was interviewed. Again on the 25th July and again on the 12th August, he was suspended that day. It took them till 20th September for the first disciplinary hearing. During that hearing my son mentioned in reply to a question that was asked that he suffered with anxiety/depression. Hearing was adjourned and they asked him to provide documented evidence from his dr. He attended the Drs the next day and she told him the company needed to apply direct to her. He contacted disciplinary manager that day, which was a Wednesday, the Thursday and the Friday, and again on the Saturday. On the Saturday he replied saying the disciplinary would continue without the note the following Tuesday 27th September. It did and he was sacked. My son was not allowed to ask one question during the disciplinary so therefore could not defend the accusation. He took it to appeal the day after and got a date in November to attend. Three weeks later 23rd December he found out he had won his appeal and was reinstated with a final written warning. He declined on the 7th January and we contacted the CEO of the company. We was put in contact with the head of HR for the north whom we met on the 2nd March. Everything had been kept under the radar the regional HR manager did not know anything about it till my son won his appeal. The head of HR admitted they had not legally conducted the disciplinary they way it should of been conducted and she agreed to start an investigation into it. My son had on,y been employed about 9 months before this incident started so he had no employment rights. The stress he was put under was that bad he was referred by his dr to a counsellor. Is there anything we can do for justice. Did they breach their contract by not following procedures.