I have just checked the site review on Trustpilot, just only 2 reviews:
https://www.trustpilot.com/review/xspeedfx.comThat means people are not using that site, it also means it is a scam site. Better not to use the site again.
You can do this, if it is crypto like bitcoin you are dealing with, check the txid given you for the withdrawal, check your transaction on blockchain explorer like
https://blockchair.com to be certain that it is a valid transaction, then check if your receiving address is correct.
But, with what I have checked about this site, I will conclude it to be a scam site.
I came to the same conclusion...
I've looked at the url you (OP) posted, the site itself is only 5 months old, the whois info is hidden, trustpilot has only 2 reviews (from accounts that made 1 review in total, i suspect them being fake reviews).
Other than that, the site itself looks suspicious to me... Can't really put my finger on it, but my gut feeling isn't good about it.
The bottom line, however, is that bitcoin is irreversible, trustless, immutable and transactions are allmost instant (eventough it might take a while untill they are confirmed, you should see an unconfirmed transaction mere seconds after it was broadcasted.... An unconfirmed transaction shouldn't be trusted tough!!!)
What i'm trying to say: only the sender can send you the funds they owe you, and if they come up with lame excuses like "we sent the funds, it's just not visible yet" (or something like that): i'm 99,9% certain they're lying.