Okay, change instructors as others have said. Some other things:
Even though i have just 5 days left on my visa i have not flown for the last 10 days when i have just 9 hours and the check ride left to do because of this one exam.
There is no, zero, nada, JAA requirement to have done any ground exam before you undertake any part of your flight training. The "air law before first solo" is a myth. The "nav before first x-country solo" is a myth. Check JAR-FCL, LASORS or the ANO if you wish. The only requirement in this respect, applicable to you, is that you need to have done a rather simple 18-question FAA exam before you are allowed to fly solo in US airspace. So if your instructor claims that you cannot fly off those last 9 hours you either haven't gone solo yet, or he's lying.
You have to have done all JAA ground exams before you show up for your flight test though.
I told my instructor i wasnt able to do this exam because it requires the ICAO map, of which there is 1 to share between the whole school and someone else had it.
The school is to provide a certain ICAO map of the UK as part of the exam papers. This is so that you cannot put your own notes on your own map. But to be honest, you don't need this particular map to prepare for the exam. You can just take any map to do your exercises, even if it's a non-ICAO (eg. Jeppesen or FAA) one.
Having said that, if the absence of a 10-quid ICAO map is really holding up your training for more than 10 days I would have ordered one online nine days ago, with overnight delivery specified.
I have never had any ground training
The school where I went to offered evening ground school classes that cycled through the whole curriculum in three weeks. They were included in the package, although I never used them. Were they included in your package? Did you make use of them?
Any groundschool outside these evening classes (except normal pre- and post flight briefings) was considered extra and had to be paid for. That's only fair, in my opinion.
When i joined the school i was just given the ppl confuser and told to go and study, there was no mentions of having to do certain exams before a certain time , there are not even any books or resources for the students to use if the confuser isnt enough.
The school I went to specified that you had to buy your own set of books, and even provided a link where you could get them. You were supposed to study as much as you could before you showed up. There were a few confusers that were lying in the briefing room and were donated by previous students "to all future students". They were technically not owned by the school although the school encouraged its use.
Needless to say, you should have gotten these books as soon as you could, even if it meant an overnight Fedex delivery from the UK to the US. You can NOT expect to learn all PPL theory from the confuser alone.
When i leave next week i know i will have completed all of the exams and have just 5 hours left to do before my check ride, is it easy to get this done at a school in the UK when im back?
Yes. No problem whatsoever, although you'll probably need a few hours to get used to local procedures, airspace, R/T and such. Make sure that all your paperwork is complete and signed off by the school, including signatures and a stamp from the school saying that your logbook entries have been verified and are correct.