It may be that Daisy / Vivaciti have started to allocate addresses from an IPv4 block previously used in Greece. This sort of thing may become more common as the IPv4 address space is fully allocated, meaning new allocations must be made by reallocating previously used IPv4 space. The effect is a bit like getting calls for the previous user of a reallocated phone number.
As a matter of interest, what does
RIPE Whois say when you enter your IP address?
The geolocation databases are far from perfect. On my wired machines, which cannot send GPS data or Wi-Fi SSIDs, Google's geolocation engine is convinced I'm in Billericay. I have no idea why, as Zen are in the Manchester area and the /28 IPv4 block allocated to my network has been allocated to me (in Bedfordshire) since July 2005. You'd have thought Google would have noticed the only traffic from devices with GPS and/or Wi-Fi on our NAT IP address comes from Bedfordshire by now.
It's rare for the geolocation databases to have an IP address listed in the wrong country.
It is probably worth the original poster raising this issue with his ISP, as they should be able to persuade Google to correct the country data.