Multiple send transactions of BTC create a conflict. The mempool is where all the valid transactions wait to be confirmed by the Bitcoin network. BTC will not allow subsequent transactions until the first transaction is confirmed. If you have multiple pending BTC transactions and only one was successful, please quit the Arculus Wallet app (or force close, if necessary). This will wipe the pending transactions and restore your balance. You can then try the transactions again, but we recommend that you make sure each transaction is confirmed before attempting the next transaction. This should allow the send transactions to get to the mempool successfully.