I dont wish to be called by my surname

with my surname and then san at the end when I go to JPN in Oct,

can't I just ask to be called Abhi-sama or something

or just ask peeps to call me Abhi as the surname and san doesn't really do it for me

How about just asking them to call you Abhi.

When you introduce yourself to people say "Abhi to yonde kudasai".

It means "please call me Abhi".

But don't ask people to call you Abhi-sama as "sama" is a very formal and polite way of referring to someone usually of higher rank than you or someone you wish to show respect to. Asking people to call you that could come of as egotistical or arrogant or, at the very least, ignorant.

check out this page for more info on Japanese honorifics

http://en.wikipedia.org/wiki/Japanese_titles

I am almost never called by my surname in Japan- only at government offices or banks when I am called back to the desk after making an application of some kind.

You are just travelling, right? It is unlikely you will be in many situations where people will need to call you by any name at all, in that case. If you are planning to join some kind of group or are going to make a big effort to make Japanese friends in the short time you are here, just tell them your name is Abhi, and that's what they will call you.

As above, never use either san or sama in relation to your own name, it's just not done.

I've been here for about 10months now and I've never had anyone call me by my surname, mainly because I just tell them my given name and they call me by that. So no worries. Just tell people whatever name you want them to call you by and they will.

First of all, you will look like a fool if you refer to yourself with a suffix as this is only used by other people - never the owner of the name. Second, ''sama'' is not a very appropriate suffix as it is used for someone highly respectable like your company's boss. Just imagine if I visited someone's family and I said to them ''Please, by all means, call me Sir Smith''... sounds kinda snooty and arrogant, right? :P

As SH said, people will call you Abhi if you tell them that's your name. But be prepared for them to add "san" because that's like saying mister. It's just polite so accept it. I lived there 9 years so I know.
At my company I was always Dick-san. Outside I was "surname-san".