Не работает последний if при проверки длины конечного результата

    def phone_number(number):
    allowed_characters = '+()-1234567890'
    symvols = ['-', '(', ')']
    for num in range(len(number)):
        if number[num] not in allowed_characters:           # Check allowed char
            return 'Not correct'
    #########
    if number[0] == '8':                                       # replase 8 with +7
        number = '+7' + number[1::]
    elif number[0] == '+' and number[1] == '7':                # checking where the number starts.
        print(number)
    else:
        print(number)
    #######
    if number[0] != '+':                             # Check правильность +
        return 'Not correct'
    ########
    for char in number:      # Check () and del
        if char not in symvols:
            number = list(number)
            step = 0
            if number[2 + step] == '(':
                del number[2 + step]
                step -= 1
            if number[6 + step] == ')':
                del number[6 + step]
                step -= 1
            if number[10 + step] == '-':
                del number[10 + step]
                step -= 1
            if ((13 + step) < len(number)) and (number[13 + step] == '-'):
                del number[13 + step]
            elif number [8] == '-' or number[10] == '-':
                del number[8]
                del number[10]
            return ''.join(number)

        if len(number[1::]) != 11:               !!!!! Вот эта часть
            return 'Not correct'
        else:
            return number

print(phone_number(input('Введите номер:')))