Status: 0/unconfirmed
Date: 14/06/2016 12:59
To: Send to  wallet 1ESz2tJ35T1VU9KA2JHHTjXEuWhP9Xgqj2
Debit: -0.01065500 BTC
Net amount: -0.01065500 BTC
Transaction ID: 3797806a3b79df6588222329c1641809577506a796f8cbc0dc4d67a3b857b678-000

As you can see, I sent the above on 14/06/16 and still have no confirmations to date.
I am using Bitcoin Core wallet version v0.10.3 (64-bit) and cannot update as I am running OS X 10.6.8

I sent with a small fee, but the tickbox "send as a zero-fee transaction if possible" was ticked.

Have read the pages in the forum and see that people keep giving the advice to cancel the transaction and resend with a higher fee or to double spend.

Cannot see any way of cancelling the transaction. Have looked everywhere within Bitcoin core several times and do not see any option to cancel a transaction.

I need somebody to explain VERY simply how I achieve this or how you would be able to double spend.

I have sent many bitcoins to other addresses since and had no problems, but I still have the no confirmations with the above transaction.

Can anyone help?

Electrum sometimes does not update its data from the server, not sure why but restarting it usually fixes it. Its not that there were 1151 blocks found in quick succession, but that your wallet was out of sync for almost 8 days.

blockchain.info is not the blockchain, neither it is a full report of transactions going through the bitcoin network at any given time.
There are plenty of reasons explaining why a transaction was sent by someone and you don't see it on blockchain.info.

Hello, what can i do to complete the transaction? Here is my problem: https://blockchain.info/tx/c8847648f5d23e02fccfeb727cd3cd3067a300db20a0212f4b2a478a9b73e851 , I using bitcoin core and I don't know what to do. I wait 7days but still nothing. Help! please

Given the lack of a fee it might never go through as is as it competes with fee-paying transactions.  If you arrange for your wallet to stop retransmitting the transaction then eventually the network should forget it.  I haven't done it myself but apparently the right-click abandon transaction is the thing you need.  After that then you can send a new transaction with an appropriate fee which will go through in a reasonable amount of time.

Your fee of 50 satoshi per byte is half of what is recommended which is 100 satoshi per byte. It may confirm soon but there's no guarantee. If you want it to be confirmed faster try doing what I posted here.

Since you are using a web wallet, you likely don't have much control so it will be difficult or impossible to perform an RBF transaction. All you can do is wait. You can try contacting Quickseller and macbook-air as they are known to have been able to help people with this.

No it is not. Your fee is ~65 satoshis/byte. According to http://bitcoinfees.21.co/ the current recommended fee is 100 satoshis/byte.

No. Bitcoin does not just "disappear" or magically become lost due to an unconfirmed transaction. Either the transaction will be "forgotten" and your wallet will revert to a state where that transaction never happened (i.e. it "returns" to your wallet) or the transaction will confirm and the Bitcoin will go to the intended recipient.

Contact Quickseller and macbook-air as I said in my first response to you.

All wallets will require that you send a transaction fee. The transaction fee does not go to the wallet developers or the service running the wallet but rather to the miner who confirms your transaction. The fee is really an incentive for the miner to include your transaction sooner rather than later.