Has anyone experienced this before with Blockchain.info wallet?
Is there a set time limit wherein this transaction will be cancelled and my BTC be returned to my account?
Also, has anyone tried the likes of
https://www.bitcoinaccelerator.net/ and does it really work and not a scam?
I experienced it a few times I always place a specific fee to avoid transactions getting stucked and rarely use their regular fee.
There is no time limit for this but a bitcoin transaction can get rejected if it doesn't confirm after a few days or more. If you don't want this to happen you need to push your transaction.
Use this
website as a guide next time your making a bitcoin transaction.