1. Thank you for calling.
谢谢您打电话来。
还能这样说：
It is nice of you to call.
Thanks for calling me.
应用解析：
call off 取消，叫走，使转移；
call on 拜访，要求，招致，指名；
call out at 对某人高声叫喊；
call over 点名；
call round 拜访
2. I've enjoyed talking to you.
同你谈话很愉快。
还能这样说：
It's nice talking with you.
Talking with you is a great pleasure.
谚语：
To teach a pig to play on a flute.
对牛弹琴。
3. I've got to hang up now.
我得挂电话了。
还能这样说：
I've to end the phone now.
I'll have to ring off now.
应用解析：
Really now! (=Now Really!)
哎呀！真的吗！不会吧！
4. I would not delay your precious time.
我不耽误您宝贵的时间了。
还能这样说：
I won't take any more of your time.
I won't keep you any longer.
应用解析：
admit of no delay 刻不容缓；
without delay 赶快，立刻；
unreasonable delay 无理的拖延；
delay in payment 延期付款