Help, Advice, please..

We have a MIKROTIK 2.4ghz wireless running over water, distance of 2.3 klm.
We have been enjoying 20/20 meg bidirectional for many years and slower version before that.
We have been running at much slower speeds for 2 weeks and nobody seems to know what to do.
I understand at base station is a multi head and our end a single direction head.
The recent storm we lost power for 5 days.. and when back online this connection is now 3.3/8.5 avg.
The original people who set it up are gone..
I need person(s) with knowledge and skills to get it fixed, updated, whatever.
We will have NBN in October, but would like this as backup anyway.
The multi head station is apparently up a pole, with a metal pole and then a fibreglass pole.
Have never seen it, but this is how it was described to me.
I assume we are best replacing it with new, need a scaffolding person and knowledge how to align.
They did all this before, so we know it all can work and very reliably.

Any help, greatly appreciated.

Phil (0418) 441304 sherlock@sherlock.com.au