We had two shipped over from the UK but neither lasted more than a few months due to the high winds we get living on a mountainside.
We have now got one made from steel tube, not aluminium, which was made for us by the guy in Istron who makes the beach umbrellas for the local beaches. It did cost us 100 Euros but it is nuclear bomb proof and should last many more years.
Can I suggest that you find your local manufacturer of beach umbrellas and ask him or, failing that, PM me and I will give you details of the guy who made ours for us.
Too far from you I expect, given the fact you are in Heraklion, but one of the hardware shops in the West, in Kalives, near Piscines Ideale does get them in. They do seem to sell out rather quickly, however, so probably not worth making a trip to check their stock out.
As John says better to have one made or buy from Amazon and have it delivered.