Rover owners: Please help - my Rover 25 locks/immobiliser/alarm have gone a bit doolally

Hello,

Please forgive me as I know there are already posts on this topic, but they all seem to use the LUCAS system, while I have the Pektron System.

I am also not very technical at all.

I have a Rover 25 Impression. Drove it from London to Bristol and back on the weekend so you would think the battery would be fully charged.
On Monday I went to drive the car, the plip unlock worked but the alarm started sounding immediately and the driver's side indicator light was flashing.
Eventually the alarm stopped, plip was not not working, the engine would not start.
I locked the doors manually.

Thought the battery might be low due to not charging or something, so removed the battery and charged it overnight.

Put the battery back in the car but still no joy, wouldn't start, luckily no alarm sounding but there was a steady 'ticking' noise coming from under the bonnet.

Called Green Flag as we have Home Start and thought they might be able to fix it and save me a trip to the garage.

Plip unlock would not work on either fob, but he was able to unlock manually (no alarm sound). Engine would not start.

He attached his mobile battery pack with jump leads to the battery I had charged overnight and tried starting using the key. Engine tried to get going but would not start. Tried a couple of times but no joy.

Tried locking/unlocking on plip from within the car but car did not lock/unlock.

Tried starting again and engine came to life and stayed running! Hurrah!

Unplugged battery pack. Was able to start car. Hurrah!

Ticking noise from beneath the bonnet still happening for about 15 minutes but eventually stopped after starting the engine again.

However. Neither plip is working so door must be manually locked/unlocked. Also, the red light on the dashboard that usually flashes when the car is locked is not flashing.

I am GUESSING that perhaps something is wrong with the immobiliser or fobs?

I know my EKA code, and gave that a go, turning it in the lock the required number of times, then waiting 5 minutes and starting the car... but the fobs still don't work. I think this reset may only work for the LUCAS fobs?

Any help or advice would be gratefully received. As I said, I'm not very technical at all, and while it is not real hardship to use the keys and manually unlock, I'd rather it worked properly with the alarm and immobiliser and I'm in London and I do worry about my little car parked on the road