Transaction processing with multiple model updates in one set is not successful in rails

class AccountTransactionsController<ApplicationController
 def create
 begin
  ActiveRecord::Base.transaction {
    @account_transaction=AccountTransaction.new(
      withdrawal_account_id —current_user.basic_income_account.id,
      deposit_account_id:BasicIncomeAccount.find_by(account_number:params[:account_transaction][:deposit_account_id]).id,
      amount:params [:account_transaction] [:amount]
      )
    @account_transaction.save!

    # The following code is for recording in your BasicIncomeAccount
    @withdrawal_basic_income_account=current_user.basic_income_account
    @deposit_basic_come_account=BasicIncomeAccount.find_by(account_number:params[:account_transaction][:deposit_account_id])

    @amount=params[:account_transaction][:amount].to_f
    # Attempts to update both accounts traded on the following two lines failed
    @withdrawal_basic_income_account.update(balance: @withdrawal_basic_income_account.balance-@amount)
    @deposit_basic_income_account.update(balance:@deposit_basic_income_account.balance+@amount)

  }

  redirect_to root_path
rescue#Exception=>e
  flash[:notice] = "Failed.Try again."
  render "new"
end