Vauxhall Vivaro cooling system headache !!

See below in brackets for the feed i was reading.
I seem to have the exact same issue.
Some great advice was left for the user but it was never followed up? Did it work, what happened in the end?

(Here's the content from the problem you were reading
The problem is, on a regular basis the temp on the van shoots right up and the electric fan comes on, so I look to see if I need water and coolant/ antifreeze and it looks like I do, I wait for everything to cool down (even waited until next day sometimes) and the expansion tank is still looking nearly empty but when I undo the top it refills and sometimes overflows, spoken to different garages and now my head is spinning please can somebody just give me some honest answers!!)