ProTip: If you're not clever, don't try to be clever.
In all seriousness, I don't whether to pity, or laugh at the Darwin-esque situation that's unfolded.
If you just wanted to vent, objective achieved. If you actually want to make progress by taking time out to write to them, you'd do well to consider re-writing the whole thing.
Complaints (as opposed to indulgent rants) should be clear and concise. Know what you want to acheive if someone actually reads your letter. Are you asking for the warranty claim to be re-considered? Why? What do you disagree with, and why? Give them a carrot, what would make you a happy customer? What figure makes all this go away? Be objective, not subjective. For your complaint to be worth sending it ought to paint a picture whereby your objective is the most fair outcome.
Try not to let yourself get wound up by over-opinionated front-line staff. They are paid to log calls and advise company policy, anything else you get for free is worthless, and should be treated as such. Be polite at all times. In complaining you are starting the escalation process, and should eventually encounter people authorised to resolve issues. If you alienate people, you are much less likely to achieve anything productive and he pocess wl take a lot longer.
Consider the time and effort involved on your part. Your letter mentions £30, but I can only assume that you are after more than 30 quid for it to be worthwhile putting pen to paper? If it's not worth your time to complain properly, put it down to experience and learn a lesson for next time...
